CDVWKWebViewEngine.m

/*
 Licensed to the Apache Software Foundation (ASF) under one
 or more contributor license agreements.  See the NOTICE file
 distributed with this work for additional information
 regarding copyright ownership.  The ASF licenses this file
 to you under the Apache License, Version 2.0 (the
 "License"); you may not use this file except in compliance
 with the License.  You may obtain a copy of the License at

 http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing,
 software distributed under the License is distributed on an
 "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 KIND, either express or implied.  See the License for the
 specific language governing permissions and limitations
 under the License.
 */

#import <Cordova/NSDictionary+CordovaPreferences.h>
#import <MobileCoreServices/MobileCoreServices.h>
#import <AVFoundation/AVFoundation.h>
#import <objc/message.h>
#import <objc/runtime.h>

#import "CDVWKWebViewEngine.h"
#import "CDVWKWebViewUIDelegate.h"
#import "CDVWKProcessPoolFactory.h"
#import "IONAssetHandler.h"

#define CDV_BRIDGE_NAME @"cordova"
#define CDV_IONIC_STOP_SCROLL @"stopScroll"
#define CDV_SERVER_PATH @"serverBasePath"
#define LAST_BINARY_VERSION_CODE @"lastBinaryVersionCode"
#define LAST_BINARY_VERSION_NAME @"lastBinaryVersionName"

@implementation UIScrollView (BugIOS11)

+ (void)load {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        Class class = [self class];
        SEL originalSelector = @selector(init);
        SEL swizzledSelector = @selector(xxx_init);

        Method originalMethod = class_getInstanceMethod(class, originalSelector);
        Method swizzledMethod = class_getInstanceMethod(class, swizzledSelector);

        BOOL didAddMethod =
        class_addMethod(class,
                        originalSelector,
                        method_getImplementation(swizzledMethod),
                        method_getTypeEncoding(swizzledMethod));

        if (didAddMethod) {
            class_replaceMethod(class,
                                swizzledSelector,
                                method_getImplementation(originalMethod),
                                method_getTypeEncoding(originalMethod));
        } else {
            method_exchangeImplementations(originalMethod, swizzledMethod);
        }
    });
}

#pragma mark - Method Swizzling

- (id)xxx_init {
    id a = [self xxx_init];
    NSArray *stack = [NSThread callStackSymbols];
    for(NSString *trace in stack) {
        if([trace containsString:@"WebKit"]) {
            [a setContentInsetAdjustmentBehavior:UIScrollViewContentInsetAdjustmentNever];
            break;
        }
    }
    return a;
}

@end


@interface CDVWKWeakScriptMessageHandler : NSObject <WKScriptMessageHandler>

@property (nonatomic, weak, readonly) id<WKScriptMessageHandler>scriptMessageHandler;

- (instancetype)initWithScriptMessageHandler:(id<WKScriptMessageHandler>)scriptMessageHandler;

@end


@interface CDVWKWebViewEngine ()

@property (nonatomic, strong, readwrite) UIView* engineWebView;
@property (nonatomic, strong, readwrite) id <WKUIDelegate> uiDelegate;
@property (nonatomic, weak) id <WKScriptMessageHandler> weakScriptMessageHandler;
@property (nonatomic, readwrite) CGRect frame;
@property (nonatomic, strong) NSString *userAgentCreds;
@property (nonatomic, strong) IONAssetHandler * handler;

@property (nonatomic, readwrite) NSString *CDV_LOCAL_SERVER;
@end

// expose private configuration value required for background operation
@interface WKWebViewConfiguration ()

@end


// see forwardingTargetForSelector: selector comment for the reason for this pragma
#pragma clang diagnostic ignored "-Wprotocol"

@implementation CDVWKWebViewEngine

@synthesize engineWebView = _engineWebView;

- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super init];
    if (self) {
        if (NSClassFromString(@"WKWebView") == nil) {
            return nil;
        }
        // add to keyWindow to ensure it is 'active'
        [UIApplication.sharedApplication.keyWindow addSubview:self.engineWebView];

        self.frame = frame;
    }
    return self;
}

-(NSString *) getStartPath {
    NSString * wwwPath = [[NSBundle mainBundle] pathForResource:@"www" ofType: nil];

    NSUserDefaults* userDefaults = [NSUserDefaults standardUserDefaults];
    NSString * persistedPath = [userDefaults objectForKey:CDV_SERVER_PATH];
    if (![self isDeployDisabled] && ![self isNewBinary] && persistedPath && ![persistedPath isEqualToString:@""]) {
        NSString *libPath = [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES) objectAtIndex:0];
        NSString * cordovaDataDirectory = [libPath stringByAppendingPathComponent:@"NoCloud"];
        NSString * snapshots = [cordovaDataDirectory stringByAppendingPathComponent:@"ionic_built_snapshots"];
        wwwPath = [snapshots stringByAppendingPathComponent:[persistedPath lastPathComponent]];
    }
    self.basePath = wwwPath;
    return wwwPath;
}

-(BOOL) isNewBinary
{
    NSString * versionCode = [[NSBundle mainBundle] infoDictionary][@"CFBundleVersion"];
    NSString * versionName = [[NSBundle mainBundle] infoDictionary][@"CFBundleShortVersionString"];
    NSUserDefaults * prefs = [NSUserDefaults standardUserDefaults];
    NSString * lastVersionCode = [prefs stringForKey:LAST_BINARY_VERSION_CODE];
    NSString * lastVersionName = [prefs stringForKey:LAST_BINARY_VERSION_NAME];
    if (![versionCode isEqualToString:lastVersionCode] || ![versionName isEqualToString:lastVersionName]) {
        [prefs setObject:versionCode forKey:LAST_BINARY_VERSION_CODE];
        [prefs setObject:versionName forKey:LAST_BINARY_VERSION_NAME];
        [prefs setObject:@"" forKey:CDV_SERVER_PATH];
        [prefs synchronize];
        return YES;
    }
    return NO;
}

-(BOOL) isDeployDisabled {
    return [[self.commandDelegate.settings objectForKey:[@"DisableDeploy" lowercaseString]] boolValue];
}

- (WKWebViewConfiguration*) createConfigurationFromSettings:(NSDictionary*)settings
{
    WKWebViewConfiguration* configuration = [[WKWebViewConfiguration alloc] init];
    configuration.processPool = [[CDVWKProcessPoolFactory sharedFactory] sharedProcessPool];
    configuration.mediaTypesRequiringUserActionForPlayback = WKAudiovisualMediaTypeNone;

    if (settings == nil) {
        return configuration;
    }

    if(![settings cordovaBoolSettingForKey:@"WKSuspendInBackground" defaultValue:YES]){
        NSString* _BGStatus;
        if (@available(iOS 12.2, *)) {
            // do stuff for iOS 12.2 and newer
            NSLog(@"iOS 12.2+ detected");
            NSString* str = @"YWx3YXlzUnVuc0F0Rm9yZWdyb3VuZFByaW9yaXR5";
            NSData* data  = [[NSData alloc] initWithBase64EncodedString:str options:0];
            _BGStatus = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
        } else {
            // do stuff for iOS 12.1 and older
            NSLog(@"iOS Below 12.2 detected");
            NSString* str = @"X2Fsd2F5c1J1bnNBdEZvcmVncm91bmRQcmlvcml0eQ==";
            NSData* data  = [[NSData alloc] initWithBase64EncodedString:str options:0];
            _BGStatus = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
        }
        [configuration setValue:[NSNumber numberWithBool:YES]
                         forKey:_BGStatus];
    }
    NSString *userAgent = configuration.applicationNameForUserAgent;
    if (
        [settings cordovaSettingForKey:@"OverrideUserAgent"] == nil &&
        [settings cordovaSettingForKey:@"AppendUserAgent"] != nil
        ) {
        userAgent = [NSString stringWithFormat:@"%@ %@", userAgent, [settings cordovaSettingForKey:@"AppendUserAgent"]];
    }
    configuration.applicationNameForUserAgent = userAgent;
    configuration.allowsInlineMediaPlayback = [settings cordovaBoolSettingForKey:@"AllowInlineMediaPlayback" defaultValue:YES];
    configuration.suppressesIncrementalRendering = [settings cordovaBoolSettingForKey:@"SuppressesIncrementalRendering" defaultValue:NO];
    configuration.allowsAirPlayForMediaPlayback = [settings cordovaBoolSettingForKey:@"MediaPlaybackAllowsAirPlay" defaultValue:YES];
    return configuration;
}

- (void)pluginInitialize
{
    // viewController would be available now. we attempt to set all possible delegates to it, by default
    NSDictionary* settings = self.commandDelegate.settings;
    NSString *bind = [settings cordovaSettingForKey:@"Hostname"];
    if(bind == nil){
        bind = @"localhost";
    }
    NSString *scheme = [settings cordovaSettingForKey:@"iosScheme"];
    if(scheme == nil || [scheme isEqualToString:@"http"] || [scheme isEqualToString:@"https"]  || [scheme isEqualToString:@"file"]){
        scheme = @"ionic";
    }
    self.CDV_LOCAL_SERVER = [NSString stringWithFormat:@"%@://%@", scheme, bind];

    self.uiDelegate = [[CDVWKWebViewUIDelegate alloc] initWithTitle:[[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleDisplayName"]];

    CDVWKWeakScriptMessageHandler *weakScriptMessageHandler = [[CDVWKWeakScriptMessageHandler alloc] initWithScriptMessageHandler:self];

    WKUserContentController* userContentController = [[WKUserContentController alloc] init];
    [userContentController addScriptMessageHandler:weakScriptMessageHandler name:CDV_BRIDGE_NAME];
    [userContentController addScriptMessageHandler:weakScriptMessageHandler name:CDV_IONIC_STOP_SCROLL];

    // Inject XHR Polyfill
    NSLog(@"CDVWKWebViewEngine: trying to inject XHR polyfill");
    WKUserScript *wkScript = [self wkPluginScript];
    if (wkScript) {
        [userContentController addUserScript:wkScript];
    }

    WKUserScript *configScript = [self configScript];
    if (configScript) {
        [userContentController addUserScript:configScript];
    }

    BOOL autoCordova = [settings cordovaBoolSettingForKey:@"AutoInjectCordova" defaultValue:NO];
    if (autoCordova){
        NSLog(@"CDVWKWebViewEngine: trying to inject XHR polyfill");
        WKUserScript *cordova = [self autoCordovify];
        if (cordova) {
            [userContentController addUserScript:cordova];
        }
    }

    BOOL audioCanMix = [settings cordovaBoolSettingForKey:@"AudioCanMix" defaultValue:NO];
    if (audioCanMix) {
        [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayAndRecord
                                         withOptions:AVAudioSessionCategoryOptionMixWithOthers
                                               error:nil];
    }

    WKWebViewConfiguration* configuration = [self createConfigurationFromSettings:settings];
    configuration.userContentController = userContentController;

    self.handler = [[IONAssetHandler alloc] initWithBasePath:[self getStartPath] andScheme:scheme];
    [configuration setURLSchemeHandler:self.handler forURLScheme:scheme];

    // re-create WKWebView, since we need to update configuration
    // remove from keyWindow before recreating
    [self.engineWebView removeFromSuperview];
    WKWebView* wkWebView = [[WKWebView alloc] initWithFrame:self.frame configuration:configuration];

    [wkWebView.scrollView setContentInsetAdjustmentBehavior:UIScrollViewContentInsetAdjustmentNever];

    wkWebView.UIDelegate = self.uiDelegate;
    self.engineWebView = wkWebView;
    // add to keyWindow to ensure it is 'active'
    [UIApplication.sharedApplication.keyWindow addSubview:self.engineWebView];

    NSString * overrideUserAgent = [settings cordovaSettingForKey:@"OverrideUserAgent"];
    if (overrideUserAgent != nil) {
        wkWebView.customUserAgent = overrideUserAgent;
    }

    if ([self.viewController conformsToProtocol:@protocol(WKUIDelegate)]) {
        wkWebView.UIDelegate = (id <WKUIDelegate>)self.viewController;
    }

    if ([self.viewController conformsToProtocol:@protocol(WKNavigationDelegate)]) {
        wkWebView.navigationDelegate = (id <WKNavigationDelegate>)self.viewController;
    } else {
        wkWebView.navigationDelegate = (id <WKNavigationDelegate>)self;
    }

    if ([self.viewController conformsToProtocol:@protocol(WKScriptMessageHandler)]) {
        [wkWebView.configuration.userContentController addScriptMessageHandler:(id < WKScriptMessageHandler >)self.viewController name:CDV_BRIDGE_NAME];
    }

    [self keyboardDisplayDoesNotRequireUserAction];

    if ([settings cordovaBoolSettingForKey:@"KeyboardAppearanceDark" defaultValue:NO]) {
        [self setKeyboardAppearanceDark];
    }
    
    #if __IPHONE_OS_VERSION_MAX_ALLOWED >= 160400
        // With the introduction of iOS 16.4 the webview is no longer inspectable by default.
        // We'll honor that change for release builds, but will still allow inspection on debug builds by default.
        // We also introduce an override option, so consumers can influence this decision in their own build.
        if (@available(iOS 16.4, *)) {
    #ifdef DEBUG
            BOOL allowWebviewInspectionDefault = YES;
    #else
            BOOL allowWebviewInspectionDefault = NO;
    #endif
            wkWebView.inspectable = [settings cordovaBoolSettingForKey:@"InspectableWebview" defaultValue:allowWebviewInspectionDefault];
        }
    #endif
    [self updateSettings:settings];

    // check if content thread has died on resume
    NSLog(@"%@", @"CDVWKWebViewEngine will reload WKWebView if required on resume");
    [[NSNotificationCenter defaultCenter]
     addObserver:self
     selector:@selector(onAppWillEnterForeground:)
     name:UIApplicationWillEnterForegroundNotification object:nil];

    // If less than ios 13.4
    if (@available(iOS 13.4, *)) {} else {
        // For keyboard dismissal leaving viewport shifted (can potentially be removed when apple releases the fix for the issue discussed here: https://github.com/apache/cordova-ios/issues/417#issuecomment-423340885)
        // Apple has released a fix in 13.4, but not in 12.x (as of 12.4.6)
        [[NSNotificationCenter defaultCenter]
        addObserver:self
        selector:@selector(keyboardWillHide)
        name:UIKeyboardWillHideNotification object:nil];
    }

    NSLog(@"Using Ionic WKWebView");

}

// https://github.com/Telerik-Verified-Plugins/WKWebView/commit/04e8296adeb61f289f9c698045c19b62d080c7e3#L609-L620
- (void) keyboardDisplayDoesNotRequireUserAction {
    Class class = NSClassFromString(@"WKContentView");
    NSOperatingSystemVersion iOS_11_3_0 = (NSOperatingSystemVersion){11, 3, 0};
    NSOperatingSystemVersion iOS_12_2_0 = (NSOperatingSystemVersion){12, 2, 0};
    NSOperatingSystemVersion iOS_13_0_0 = (NSOperatingSystemVersion){13, 0, 0};
    char * methodSignature = "_startAssistingNode:userIsInteracting:blurPreviousNode:changingActivityState:userObject:";

    if ([[NSProcessInfo processInfo] isOperatingSystemAtLeastVersion: iOS_13_0_0]) {
         methodSignature = "_elementDidFocus:userIsInteracting:blurPreviousNode:activityStateChanges:userObject:";
     } else if ([[NSProcessInfo processInfo] isOperatingSystemAtLeastVersion: iOS_12_2_0]) {
        methodSignature = "_elementDidFocus:userIsInteracting:blurPreviousNode:changingActivityState:userObject:";
    }

    if ([[NSProcessInfo processInfo] isOperatingSystemAtLeastVersion: iOS_11_3_0]) {
        SEL selector = sel_getUid(methodSignature);
        Method method = class_getInstanceMethod(class, selector);
        IMP original = method_getImplementation(method);
        IMP override = imp_implementationWithBlock(^void(id me, void* arg0, BOOL arg1, BOOL arg2, BOOL arg3, id arg4) {
            ((void (*)(id, SEL, void*, BOOL, BOOL, BOOL, id))original)(me, selector, arg0, TRUE, arg2, arg3, arg4);
        });
        method_setImplementation(method, override);
    } else {
        SEL selector = sel_getUid("_startAssistingNode:userIsInteracting:blurPreviousNode:userObject:");
        Method method = class_getInstanceMethod(class, selector);
        IMP original = method_getImplementation(method);
        IMP override = imp_implementationWithBlock(^void(id me, void* arg0, BOOL arg1, BOOL arg2, id arg3) {
            ((void (*)(id, SEL, void*, BOOL, BOOL, id))original)(me, selector, arg0, TRUE, arg2, arg3);
        });
        method_setImplementation(method, override);
    }
}

- (void)setKeyboardAppearanceDark
{
    IMP darkImp = imp_implementationWithBlock(^(id _s) {
        return UIKeyboardAppearanceDark;
    });
    for (NSString* classString in @[@"WKContentView", @"UITextInputTraits"]) {
        Class c = NSClassFromString(classString);
        Method m = class_getInstanceMethod(c, @selector(keyboardAppearance));
        if (m != NULL) {
            method_setImplementation(m, darkImp);
        } else {
            class_addMethod(c, @selector(keyboardAppearance), darkImp, "l@:");
        }
    }
}



- (void)onAppWillEnterForeground:(NSNotification *)notification {
    if ([self shouldReloadWebView]) {
        NSLog(@"%@", @"CDVWKWebViewEngine reloading!");
        [(WKWebView*)_engineWebView reload];
    }
}


-(void)keyboardWillHide
{
    // For keyboard dismissal leaving viewport shifted (can potentially be removed when apple releases the fix for the issue discussed here: https://github.com/apache/cordova-ios/issues/417#issuecomment-423340885)
    UIScrollView * scrollView = self.webView.scrollView;
    // Calculate some vars for convenience
    CGFloat contentLengthWithInsets = scrollView.contentSize.height + scrollView.adjustedContentInset.top + scrollView.adjustedContentInset.bottom;
    CGFloat contentOffsetY = scrollView.contentOffset.y;
    CGFloat screenHeight = scrollView.frame.size.height;
    CGFloat maxAllowedOffsetY = fmax(contentLengthWithInsets - screenHeight, 0); // 0 is for the case where content is shorter than screen

    // If the keyboard allowed the user to get to an offset beyond the max
    if (contentOffsetY > maxAllowedOffsetY) {
        // Reset the scroll to the max allowed so that there is no additional empty white space at the bottom where the keyboard occupied!
        CGPoint bottomOfPage = CGPointMake(scrollView.contentOffset.x, maxAllowedOffsetY);
        [scrollView setContentOffset:bottomOfPage];
    }
}

- (BOOL)shouldReloadWebView
{
    WKWebView* wkWebView = (WKWebView*)_engineWebView;
    return [self shouldReloadWebView:wkWebView.URL title:wkWebView.title];
}

- (BOOL)shouldReloadWebView:(NSURL *)location title:(NSString*)title
{
    BOOL title_is_nil = (title == nil);
    BOOL location_is_blank = [[location absoluteString] isEqualToString:@"about:blank"];

    BOOL reload = (title_is_nil || location_is_blank);

#ifdef DEBUG
    NSLog(@"%@", @"CDVWKWebViewEngine shouldReloadWebView::");
    NSLog(@"CDVWKWebViewEngine shouldReloadWebView title: %@", title);
    NSLog(@"CDVWKWebViewEngine shouldReloadWebView location: %@", [location absoluteString]);
    NSLog(@"CDVWKWebViewEngine shouldReloadWebView reload: %u", reload);
#endif

    return reload;
}


- (id)loadRequest:(NSURLRequest *)request
{
    if (request.URL.fileURL) {
        NSURL* startURL = [NSURL URLWithString:((CDVViewController *)self.viewController).startPage];
        NSString* startFilePath = [self.commandDelegate pathForResource:[startURL path]];
        NSURL *url = [[NSURL URLWithString:self.CDV_LOCAL_SERVER] URLByAppendingPathComponent:request.URL.path];
        if ([request.URL.path isEqualToString:startFilePath]) {
            url = [NSURL URLWithString:self.CDV_LOCAL_SERVER];
        }
        if(request.URL.query) {
            url = [NSURL URLWithString:[@"?" stringByAppendingString:request.URL.query] relativeToURL:url];
        }
        if(request.URL.fragment) {
            url = [NSURL URLWithString:[@"#" stringByAppendingString:request.URL.fragment] relativeToURL:url];
        }
        request = [NSURLRequest requestWithURL:url];
    }
    return [(WKWebView*)_engineWebView loadRequest:request];
}

- (id)loadHTMLString:(NSString *)string baseURL:(NSURL*)baseURL
{
    return [(WKWebView*)_engineWebView loadHTMLString:string baseURL:baseURL];
}

- (NSURL*) URL
{
    return [(WKWebView*)_engineWebView URL];
}

- (BOOL)canLoadRequest:(NSURLRequest *)request
{
    return TRUE;
}

- (void)updateSettings:(NSDictionary *)settings
{
    WKWebView* wkWebView = (WKWebView *)_engineWebView;

    // By default, DisallowOverscroll is false (thus bounce is allowed)
    BOOL bounceAllowed = !([settings cordovaBoolSettingForKey:@"DisallowOverscroll" defaultValue:NO]);

    // prevent webView from bouncing
    if (!bounceAllowed) {
        if ([wkWebView respondsToSelector:@selector(scrollView)]) {
            ((UIScrollView*)[wkWebView scrollView]).bounces = NO;
        } else {
            for (id subview in wkWebView.subviews) {
                if ([[subview class] isSubclassOfClass:[UIScrollView class]]) {
                    ((UIScrollView*)subview).bounces = NO;
                }
            }
        }
    }

    wkWebView.configuration.preferences.minimumFontSize = [settings cordovaFloatSettingForKey:@"MinimumFontSize" defaultValue:0.0];
    wkWebView.allowsLinkPreview = [settings cordovaBoolSettingForKey:@"AllowLinkPreview" defaultValue:NO];
    wkWebView.scrollView.scrollEnabled = [settings cordovaBoolSettingForKey:@"ScrollEnabled" defaultValue:NO];
    wkWebView.allowsBackForwardNavigationGestures = [settings cordovaBoolSettingForKey:@"AllowBackForwardNavigationGestures" defaultValue:NO];
}

- (void)updateWithInfo:(NSDictionary *)info
{
    NSDictionary* scriptMessageHandlers = [info objectForKey:kCDVWebViewEngineScriptMessageHandlers];
    NSDictionary* settings = [info objectForKey:kCDVWebViewEngineWebViewPreferences];
    id navigationDelegate = [info objectForKey:kCDVWebViewEngineWKNavigationDelegate];
    id uiDelegate = [info objectForKey:kCDVWebViewEngineWKUIDelegate];

    WKWebView* wkWebView = (WKWebView*)_engineWebView;

    if (scriptMessageHandlers && [scriptMessageHandlers isKindOfClass:[NSDictionary class]]) {
        NSArray* allKeys = [scriptMessageHandlers allKeys];

        for (NSString* key in allKeys) {
            id object = [scriptMessageHandlers objectForKey:key];
            if ([object conformsToProtocol:@protocol(WKScriptMessageHandler)]) {
                [wkWebView.configuration.userContentController addScriptMessageHandler:object name:key];
            }
        }
    }

    if (navigationDelegate && [navigationDelegate conformsToProtocol:@protocol(WKNavigationDelegate)]) {
        wkWebView.navigationDelegate = navigationDelegate;
    }

    if (uiDelegate && [uiDelegate conformsToProtocol:@protocol(WKUIDelegate)]) {
        wkWebView.UIDelegate = uiDelegate;
    }

    if (settings && [settings isKindOfClass:[NSDictionary class]]) {
        [self updateSettings:settings];
    }
}

// This forwards the methods that are in the header that are not implemented here.
//     loadHTMLString:baseURL:
//     loadRequest:
- (id)forwardingTargetForSelector:(SEL)aSelector
{
    return _engineWebView;
}

- (UIView *)webView
{
    return self.engineWebView;
}

- (WKUserScript *)wkPluginScript
{
    NSString *scriptFile = [[NSBundle mainBundle] pathForResource:@"www/wk-plugin" ofType:@"js"];
    if (scriptFile == nil) {
        NSLog(@"CDVWKWebViewEngine: WK plugin was not found");
        return nil;
    }
    NSError *error = nil;
    NSString *source = [NSString stringWithContentsOfFile:scriptFile encoding:NSUTF8StringEncoding error:&error];
    if (source == nil || error != nil) {
        NSLog(@"CDVWKWebViewEngine: WK plugin can not be loaded: %@", error);
        return nil;
    }
    source = [source stringByAppendingString:[NSString stringWithFormat:@"window.WEBVIEW_SERVER_URL = '%@';", self.CDV_LOCAL_SERVER]];

    return [[WKUserScript alloc] initWithSource:source
                                  injectionTime:WKUserScriptInjectionTimeAtDocumentStart
                               forMainFrameOnly:YES];
}

- (WKUserScript *)configScript
{
    Class keyboard = NSClassFromString(@"CDVIonicKeyboard");
    BOOL keyboardPlugin = keyboard != nil;
    if(!keyboardPlugin) {
        return nil;
    }

    BOOL keyboardResizes = [self.commandDelegate.settings cordovaBoolSettingForKey:@"KeyboardResize" defaultValue:YES];
    NSString *source = [NSString stringWithFormat:
                        @"window.Ionic = window.Ionic || {};"
                        @"window.Ionic.keyboardPlugin=true;"
                        @"window.Ionic.keyboardResizes=%@",
                        keyboardResizes ? @"true" : @"false"];

    return [[WKUserScript alloc] initWithSource:source
                                  injectionTime:WKUserScriptInjectionTimeAtDocumentStart
                               forMainFrameOnly:YES];
}

- (WKUserScript *)autoCordovify
{
    NSURL *cordovaURL = [[NSBundle mainBundle] URLForResource:@"www/cordova" withExtension:@"js"];
    if (cordovaURL == nil) {
        NSLog(@"CDVWKWebViewEngine: cordova.js WAS NOT FOUND");
        return nil;
    }
    NSError *error = nil;
    NSString *source = [NSString stringWithContentsOfURL:cordovaURL encoding:NSUTF8StringEncoding error:&error];
    if (source == nil || error != nil) {
        NSLog(@"CDVWKWebViewEngine: cordova.js can not be loaded: %@", error);
        return nil;
    }
    NSLog(@"CDVWKWebViewEngine: auto injecting cordova");
    NSString *cordovaPath = [self.CDV_LOCAL_SERVER stringByAppendingString:cordovaURL.URLByDeletingLastPathComponent.path];
    NSString *replacement = [NSString stringWithFormat:@"var pathPrefix = '%@/';", cordovaPath];
    source = [source stringByReplacingOccurrencesOfString:@"var pathPrefix = findCordovaPath();" withString:replacement];

    return [[WKUserScript alloc] initWithSource:source
                                  injectionTime:WKUserScriptInjectionTimeAtDocumentStart
                               forMainFrameOnly:YES];
}

#pragma mark WKScriptMessageHandler implementation

- (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message
{
    if ([message.name isEqualToString:CDV_BRIDGE_NAME]) {
        [self handleCordovaMessage: message];
    } else if ([message.name isEqualToString:CDV_IONIC_STOP_SCROLL]) {
        [self handleStopScroll];
    }
}

- (void)handleCordovaMessage:(WKScriptMessage*)message
{
    CDVViewController *vc = (CDVViewController*)self.viewController;

    NSArray *jsonEntry = message.body; // NSString:callbackId, NSString:service, NSString:action, NSArray:args
    CDVInvokedUrlCommand* command = [CDVInvokedUrlCommand commandFromJson:jsonEntry];
    CDV_EXEC_LOG(@"Exec(%@): Calling %@.%@", command.callbackId, command.className, command.methodName);

    if (![vc.commandQueue execute:command]) {
#ifdef DEBUG
        NSError* error = nil;
        NSString* commandJson = nil;
        NSData* jsonData = [NSJSONSerialization dataWithJSONObject:jsonEntry
                                                           options:0
                                                             error:&error];

        if (error == nil) {
            commandJson = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
        }

        static NSUInteger maxLogLength = 1024;
        NSString* commandString = ([commandJson length] > maxLogLength) ?
        [NSString stringWithFormat : @"%@[...]", [commandJson substringToIndex:maxLogLength]] :
        commandJson;

        NSLog(@"FAILED pluginJSON = %@", commandString);
#endif
    }
}

- (void)handleStopScroll
{
    WKWebView* wkWebView = (WKWebView*)_engineWebView;
    NSLog(@"CDVWKWebViewEngine: handleStopScroll");
    [self recursiveStopScroll:[wkWebView scrollView]];
    [wkWebView evaluateJavaScript:@"window.IonicStopScroll.fire()" completionHandler:nil];
}

- (void)recursiveStopScroll:(UIView *)node
{
    if([node isKindOfClass: [UIScrollView class]]) {
        UIScrollView *nodeAsScroll = (UIScrollView *)node;

        if([nodeAsScroll isScrollEnabled] && ![nodeAsScroll isHidden]) {
            [nodeAsScroll setScrollEnabled: NO];
            [nodeAsScroll setScrollEnabled: YES];
        }
    }

    // iterate tree recursivelly
    for (UIView *child in [node subviews]) {
        [self recursiveStopScroll:child];
    }
}


#pragma mark WKNavigationDelegate implementation

- (void)webView:(WKWebView*)webView didStartProvisionalNavigation:(WKNavigation*)navigation
{
    [[NSNotificationCenter defaultCenter] postNotification:[NSNotification notificationWithName:CDVPluginResetNotification object:webView]];
}

- (void)webView:(WKWebView*)webView didFinishNavigation:(WKNavigation*)navigation
{
    #ifndef __CORDOVA_6_0_0
        CDVViewController* vc = (CDVViewController*)self.viewController;
        [CDVUserAgentUtil releaseLock:vc.userAgentLockToken];
    #endif
    [[NSNotificationCenter defaultCenter] postNotification:[NSNotification notificationWithName:CDVPageDidLoadNotification object:webView]];
}

- (void)webView:(WKWebView*)theWebView didFailProvisionalNavigation:(WKNavigation*)navigation withError:(NSError*)error
{
    [self webView:theWebView didFailNavigation:navigation withError:error];
}

- (void)webView:(WKWebView*)theWebView didFailNavigation:(WKNavigation*)navigation withError:(NSError*)error
{
    CDVViewController* vc = (CDVViewController*)self.viewController;
    #ifndef __CORDOVA_6_0_0
        [CDVUserAgentUtil releaseLock:vc.userAgentLockToken];
    #endif

    NSString* message = [NSString stringWithFormat:@"Failed to load webpage with error: %@", [error localizedDescription]];
    NSLog(@"%@", message);

    NSURL* errorUrl = vc.errorURL;
    if (errorUrl) {
        NSCharacterSet *charSet = [NSCharacterSet URLFragmentAllowedCharacterSet];
        errorUrl = [NSURL URLWithString:[NSString stringWithFormat:@"?error=%@", [message stringByAddingPercentEncodingWithAllowedCharacters:charSet]] relativeToURL:errorUrl];
        NSLog(@"%@", [errorUrl absoluteString]);
        [theWebView loadRequest:[NSURLRequest requestWithURL:errorUrl]];
    }
#ifdef DEBUG
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:[[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleDisplayName"] message:message preferredStyle:UIAlertControllerStyleAlert];
    [alertController addAction:[UIAlertAction actionWithTitle:NSLocalizedString(@"OK", nil) style:UIAlertActionStyleDefault handler:nil]];
    [vc presentViewController:alertController animated:YES completion:nil];
#endif
}

- (void)webViewWebContentProcessDidTerminate:(WKWebView *)webView
{
    [webView reload];
}

- (BOOL)defaultResourcePolicyForURL:(NSURL*)url
{
    // all file:// urls are allowed
    if ([url isFileURL]) {
        return YES;
    }

    return NO;
}

- (void) webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction*)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler
{
    NSURL* url = [navigationAction.request URL];
    CDVViewController* vc = (CDVViewController*)self.viewController;

    /*
     * Give plugins the chance to handle the url
     */
    BOOL anyPluginsResponded = NO;
    BOOL shouldAllowRequest = NO;

    for (NSString* pluginName in vc.pluginObjects) {
        CDVPlugin* plugin = [vc.pluginObjects objectForKey:pluginName];
        SEL selector = NSSelectorFromString(@"shouldOverrideLoadWithRequest:navigationType:");
        if ([plugin respondsToSelector:selector]) {
            anyPluginsResponded = YES;
            // https://issues.apache.org/jira/browse/CB-12497
            int navType = (int)navigationAction.navigationType;
            if (WKNavigationTypeOther == navigationAction.navigationType) {
                #ifdef __CORDOVA_6_0_0
                    navType = -1;
                #else
                    navType = 5;
                #endif
            }
            shouldAllowRequest = (((BOOL (*)(id, SEL, id, int))objc_msgSend)(plugin, selector, navigationAction.request, navType));
            if (!shouldAllowRequest) {
                break;
            }
        }
    }

    if (!anyPluginsResponded) {
        /*
         * Handle all other types of urls (tel:, sms:), and requests to load a url in the main webview.
         */
        shouldAllowRequest = [self defaultResourcePolicyForURL:url];
        if (!shouldAllowRequest) {
            [[NSNotificationCenter defaultCenter] postNotification:[NSNotification notificationWithName:CDVPluginHandleOpenURLNotification object:url]];
        }
    }

    if (shouldAllowRequest) {
        NSString *scheme = url.scheme;
        if ([scheme isEqualToString:@"tel"] ||
            [scheme isEqualToString:@"mailto"] ||
            [scheme isEqualToString:@"facetime"] ||
            [scheme isEqualToString:@"sms"] ||
            [scheme isEqualToString:@"maps"]) {
            [[UIApplication sharedApplication] openURL:url options:@{} completionHandler:nil];
            decisionHandler(WKNavigationActionPolicyCancel);
        } else {
            decisionHandler(WKNavigationActionPolicyAllow);
        }
    } else {
        decisionHandler(WKNavigationActionPolicyCancel);
    }
}

-(void)getServerBasePath:(CDVInvokedUrlCommand*)command
{
    [self.commandDelegate sendPluginResult:[CDVPluginResult resultWithStatus:CDVCommandStatus_OK messageAsString:self.basePath]  callbackId:command.callbackId];
}

-(void)setServerBasePath:(CDVInvokedUrlCommand*)command
{
    NSString * path = [command argumentAtIndex:0];
    self.basePath = path;
    [self.handler setAssetPath:path];

    NSURLRequest * request = [NSURLRequest requestWithURL:[NSURL URLWithString:self.CDV_LOCAL_SERVER]];
    [(WKWebView*)_engineWebView loadRequest:request];
}

-(void)persistServerBasePath:(CDVInvokedUrlCommand*)command
{
    NSUserDefaults* userDefaults = [NSUserDefaults standardUserDefaults];
    [userDefaults setObject:[self.basePath lastPathComponent] forKey:CDV_SERVER_PATH];
    [userDefaults synchronize];
}

@end

#pragma mark - CDVWKWeakScriptMessageHandler

@implementation CDVWKWeakScriptMessageHandler

- (instancetype)initWithScriptMessageHandler:(id<WKScriptMessageHandler>)scriptMessageHandler
{
    self = [super init];
    if (self) {
        _scriptMessageHandler = scriptMessageHandler;
    }
    return self;
}

- (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message
{
    [self.scriptMessageHandler userContentController:userContentController didReceiveScriptMessage:message];
}

@end